Re: [PATCH v4] dt-bindings: i2c: convert davinci i2c to dt-schema

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Omitting the 'clock-frequency' property from the device tree causes a deterministic division-by-zero crash in the driver.
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commit 75f02e0195256a57df4b6d329b0206def30928b6
Author: Chaitanya Sabnis <chaitanya.msabnis@gmail.com>

dt-bindings: i2c: convert davinci i2c to dt-schema

This commit converts the Texas Instruments DaVinci and Keystone I2C
controller bindings from legacy text format to modern dt-schema (YAML).
It also makes the interrupts property required and adds definitions for
SoC-specific hardware features.

> diff --git a/Documentation/devicetree/bindings/i2c/ti,davinci-i2c.yaml b/Documentation/devicetree/bindings/i2c/ti,davinci-i2c.yaml
> new file mode 100644
> index 0000000000000..dd7a7ffa02d54
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/i2c/ti,davinci-i2c.yaml

[ ... ]

> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +  - clocks

Should clock-frequency be included in the required list here?

Omitting the clock-frequency property from the device tree causes a
regression resulting in a division-by-zero crash in the driver.

When clock-frequency is omitted, davinci_i2c_probe() falls back to
DAVINCI_I2C_DEFAULT_BUS_FREQ (100) and calculates dev->bus_freq:

drivers/i2c/busses/i2c-davinci.c:davinci_i2c_probe() {
    ...
    dev->bus_freq = prop / 1000;
    ...
}

Due to integer truncation, dev->bus_freq becomes 0. The driver then calls
i2c_davinci_calc_clk_dividers(), which divides by dev->bus_freq:

drivers/i2c/busses/i2c-davinci.c:i2c_davinci_calc_clk_dividers() {
    ...
    clk = ((input_clock / (psc + 1)) / (dev->bus_freq * 1000));
    ...
}

This executes a division by zero during device probe. Either the C driver's
fallback logic must be corrected, or clock-frequency must be explicitly
required in the schema to prevent this regression.

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Sashiko AI review · https://sashiko.dev/#/patchset/20260513123758.4955-1-chaitanya.msabnis@gmail.com?part=1